Differential Diagnosis for Cyst vs Lipoma Draining Wound

Single Most Likely Diagnosis

• Infected Epidermoid Cyst: This is a common condition where a cyst becomes infected, leading to drainage and potentially forming a wound. The presence of a cyst that drains suggests a blocked pore or follicle that has become infected.

Other Likely Diagnoses

• Infected Lipoma: Although less common than infected cysts, lipomas can become infected, especially if they are large or if there is a history of trauma to the area. Infection can lead to drainage and wound formation.
• Abscess: An abscess is a collection of pus that can form in response to infection. It can present similarly to an infected cyst or lipoma, with drainage and wound formation.
• Furuncle or Carbuncle: These are infections of the hair follicle that can lead to drainage and wound formation. They are typically caused by Staphylococcus aureus.

Do Not Miss Diagnoses

• Necrotizing Fasciitis: Although rare, this is a life-threatening condition that requires immediate attention. It is characterized by necrosis of the fascia and can present with signs of infection, including drainage and wound formation.
• Malignancy: In rare cases, a draining wound can be a sign of an underlying malignancy, such as a squamous cell carcinoma or basal cell carcinoma. It is essential to consider this possibility, especially in non-healing wounds.

Rare Diagnoses

• Pilomatricoma: A rare, benign tumor that can become infected and drain.
• Dermoid Cyst: A rare type of cyst that can become infected and drain, although this is less common than epidermoid cysts.
• Hydatid Cyst: A parasitic infection caused by Echinococcus that can form cysts, which can become infected and drain. This is rare in many parts of the world but should be considered in endemic areas.